Ipad couldn't be restored Error4013

See this support article:--> If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch - Apple Support.

If the issue persists, contact Apple Support directly, using this link:--> http://www.apple.com/support/contact/

Regards

Giulio

From your description I presume that you are experiencing an unresponsive iPad after attempting to resolve Error #4013 - to which this support page relates?

If you see error 9, 4005, 4013, or 4014 when you restore your iPhone, iPad, or iPod touch - Apple Support

Connect your iPad to its Power Adapter and allow the iPad to charge, undisturbed, for at least an hour. While still connected to external power, try a forced-restart:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

Note:  If iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen. Or if your iPad isn’t working correctly after you restart it, see the iPad Support website.

If you continue to experience difficulties, you will need to seek assistance directly from from Apple Support. You can contact the Support Team using the Get Support link at top-right of this page. Alternatively, you can initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044

You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad:

Genius Bar Reservation and Apple Support Options - Apple

Have exactly the same issue with my 2017 iPad Pro: the 15.2.1 update ended up in bootloop. Took it to the Apple store, but they couldn't fix it either. Claimed a hardware defect, which is a bit weird as it had worked fine until the update. Hoping the next update will fix it, but for now it's bricked...